1 /*
2 * fs/nfs/nfs4renewd.c
3 *
4 * Copyright (c) 2002 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Kendrick Smith <kmsmith@umich.edu>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 *
34 * Implementation of the NFSv4 "renew daemon", which wakes up periodically to
35 * send a RENEW, to keep state alive on the server. The daemon is implemented
36 * as an rpc_task, not a real kernel thread, so it always runs in rpciod's
37 * context. There is one renewd per nfs_server.
38 *
39 */
40
41 #include <linux/mm.h>
42 #include <linux/pagemap.h>
43 #include <linux/sunrpc/sched.h>
44 #include <linux/sunrpc/clnt.h>
45
46 #include <linux/nfs.h>
47 #include <linux/nfs4.h>
48 #include <linux/nfs_fs.h>
49 #include "nfs4_fs.h"
50 #include "delegation.h"
51
52 #define NFSDBG_FACILITY NFSDBG_PROC
53
54 void
nfs4_renew_state(struct work_struct * work)55 nfs4_renew_state(struct work_struct *work)
56 {
57 const struct nfs4_state_maintenance_ops *ops;
58 struct nfs_client *clp =
59 container_of(work, struct nfs_client, cl_renewd.work);
60 struct rpc_cred *cred;
61 long lease;
62 unsigned long last, now;
63
64 ops = clp->cl_mvops->state_renewal_ops;
65 dprintk("%s: start\n", __func__);
66
67 if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
68 goto out;
69
70 spin_lock(&clp->cl_lock);
71 lease = clp->cl_lease_time;
72 last = clp->cl_last_renewal;
73 now = jiffies;
74 /* Are we close to a lease timeout? */
75 if (time_after(now, last + lease/3)) {
76 cred = ops->get_state_renewal_cred_locked(clp);
77 spin_unlock(&clp->cl_lock);
78 if (cred == NULL) {
79 if (!nfs_delegations_present(clp)) {
80 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
81 goto out;
82 }
83 nfs_expire_all_delegations(clp);
84 } else {
85 /* Queue an asynchronous RENEW. */
86 ops->sched_state_renewal(clp, cred);
87 put_rpccred(cred);
88 goto out_exp;
89 }
90 } else {
91 dprintk("%s: failed to call renewd. Reason: lease not expired \n",
92 __func__);
93 spin_unlock(&clp->cl_lock);
94 }
95 nfs4_schedule_state_renewal(clp);
96 out_exp:
97 nfs_expire_unreferenced_delegations(clp);
98 out:
99 dprintk("%s: done\n", __func__);
100 }
101
102 void
nfs4_schedule_state_renewal(struct nfs_client * clp)103 nfs4_schedule_state_renewal(struct nfs_client *clp)
104 {
105 long timeout;
106
107 spin_lock(&clp->cl_lock);
108 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
109 - (long)jiffies;
110 if (timeout < 5 * HZ)
111 timeout = 5 * HZ;
112 dprintk("%s: requeueing work. Lease period = %ld\n",
113 __func__, (timeout + HZ - 1) / HZ);
114 cancel_delayed_work(&clp->cl_renewd);
115 schedule_delayed_work(&clp->cl_renewd, timeout);
116 set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
117 spin_unlock(&clp->cl_lock);
118 }
119
120 void
nfs4_kill_renewd(struct nfs_client * clp)121 nfs4_kill_renewd(struct nfs_client *clp)
122 {
123 cancel_delayed_work_sync(&clp->cl_renewd);
124 }
125
126 /*
127 * Local variables:
128 * c-basic-offset: 8
129 * End:
130 */
131